Last week the spacecraft team installed and
tested the electronics box for MESSENGER's Magnetometer - a necessary
step before the team can install the instrument itself. Eventually
the Magnetometer sensor will be mounted on a 3.6-meter (nearly
12-foot) boom that will keep it away from the spacecraft's magnetic
field. In this view the Magnetometer electronics box is on the
bottom of the spacecraft, close to where the engineers can be
seen in the lower left..

Mercury's magnetic field (at the surface of
the planet) is about 100 times weaker than Earth's. The Magnetometer
will characterize Mercury's magnetic field in detail from orbit
over four Mercurial years -- each 88 Earth days - helping scientists
determine the field's exact strength and how that strength varies
with position and altitude. This will provide crucial clues to
help us determine the internal source of Mercury's magnetic field.